Typically in seismic surveying, energy is generated (e.g., through the use of air guns) and sent into the earth. Some of this energy is reflected back to recording sensors. This data is subsequently processed using specialized seismic data processing to generate a visual image or other data representation of the seismic survey area. Seismic surveys are conducted for a variety of reasons; they may, in some embodiments, be used for assessing where minerals and/or petroleum deposits are located.
Marine seismic surveying is typically performed by towing one or more arrays of seismic energy sources behind a survey vessel. A plurality of seismic sensor cables (e.g., seismic streamers) may also be towed by the survey vessel (or a separate vessel) at laterally spaced apart locations with respect to the center line of the survey vessel.
The source arrays may be coupled to the survey vessel by an “umbilical cable,” which provides axial strength to tow the source arrays, electrical signal conductors to actuate the individual sources and, when the seismic sources are air guns, for example compressed air lines to charge the guns between actuations.
To absorb some of the flexural motion that may be applied to an seismic source array, various portions of the array structure may include flexural sections. The flexural sections may include a tow wire, chain, cable, or similar structure to transmit axial loading and a bend restrictor to stiffen/control the flexibility. One difficulty with some embodiments of seismic source arrays is bend fatigue at the connections between flexural sections and the adjacent stiff section components, and fatigue in the stiff section components themselves.
This specification includes references to “one embodiment” or “an embodiment.” The appearances of the phrases “in one embodiment” or “in an embodiment” do not necessarily refer to the same embodiment. Particular features, structures, or characteristics may be combined in any suitable manner consistent with this disclosure.
Certain structural elements may be described herein as “configured to” or “operable to” perform one or more tasks. As used herein, these terms mean that a particular piece of hardware (in conjunction with software, in some cases) is arranged to perform a particular task or tasks when operated. Thus, a system that is “configured to” perform task A means that the system includes hardware that, during operation of the system, performs or can be used to perform task A. As such, a system can be said to be “configured to” perform task A even if the system is not currently operating. Further, certain elements may be described as “coupled” to one another. As used herein, this term includes a connection between components, whether direct or indirect.